Distant Galaxy Clusters Demonstrate Dark Energy Exists

Recent observations carried out with the XMM-Newton X-ray telescope managed to image very distant galaxy clusters in detail, providing additional evidence that dark energy, the force believed to drive the ever-accelerating universal expansion, actually exists.

The X-ray Multi-Mirror Mission – Newton mission is extremely well-equipped for such investigations. It was recently trained on the largest and most distant galaxy cluster ever seen in the Universe.

According to preliminary measurements, it would appear that the cluster tips the scale at several thousand times the mass of the Milky Way. The X-ray observatory is managed by experts at the European Space Agency (ESA).

Astrophysicists say that the mass, brightness and disposition of the massive galaxy cluster represents additional evidence that dark energy exists. It is believed to make up about 74 percent of everything in the Universe, and to be the driving force that pushes galaxies away from each other.

“This is the most luminous, and therefore probably the most massive, cluster of galaxies discovered at this epoch,” explains the leader of the XMM-Newton study, astronomer Georg Lamer.

“The light we observe started about 7.7 billion years ago. This is about half of the age of the Universe, so it is from quite long ago, and quite far away,” adds the expert, who is based at the Institute of Astrophysics, in Potsdam, Germany.

The object was discovered as experts were browsing through a catalog containing 190,000+ X-ray sources, that was created with data from the European Photon Imaging Camera (EPIC) on the telescope. The catalog covers about 1 percent of the sky.

XMM-Newton needed more than 3,500 individual observation sessions to collect data on the 190,000 radiation sources. In their search, the experts sought to identify either nearby galaxies or distant clusters of galaxies, Daily Galaxy reports.

“The very presence of this cluster [dubbed J083026+524133] confirms the existence of a mysterious component of the Universe called dark energy,” Lamer says.

“Such massive galaxy clusters are thought to be rare objects in the distant Universe. They can be used to test cosmological theories,” he concludes.